Bashir and Mason, both of Holme Park Court, Berry Brow, were remanded in custody to be sentenced at a later date.

Two 15-year-old boys and a 16-year-old boy, who cannot be named for legal reasons, have been remanded into the care of a local authority.

Detective Chief Inspector Steve Handley, the senior investigating officer, said: ‘This has been a complex and difficult murder investigation into a brutal and sustained assault on Mr Preston in summer last year.

‘Bashir, Mason and the teenage boys planned together to harm Mr Preston, which we were able to demonstrate through a combination of CCTV enquiries, forensics and telecoms work.

‘We completed extensive telephone forensics work on the mobiles of all defendants and rather horrifyingly, were able to retrieve an image of Mr Preston’s beaten body in the boot of a car on Bashir’s phone as well as many texts between all defendants planning their attack.

He added: ‘I am pleased with the result and wish to recognise the work of my investigative team who have built a significant and complex case, as well as the Crown Prosecution Service and local authority, who have worked alongside us to manage this case.

‘The three juvenile defendants, one of whom was just 14 at the time of Mr Preston’s murder, have shown no remorse for their actions, just as Bashir and Mason have denied their guilt throughout.’